The field of this invention is modular housing systems.
Prior workers in the art have conceived various modular housing systems with a certain amount of interchangeability, one of whom was George W. Rappleyea. In the patent issued to him in 1928, U.S. Pat. No. 1,689,642, Rappleyea discloses such a system in which his wall panel units are uniformly drilled, so that one wall panel can be removed and exchanged with another in a different location. The change, however, is limited to linear translation. A close reading shows that each of the Rappleyea wall panels has a fixed top end, bottom and sides, and can not be rotated about either a vertical axis or a horizontal axis without destroying its fit to the balance of his building. Such a limitation is a disadvantage to the builder, as it requires him to stack and move his panels in particular ways to avoid waste motion, and limits the pool of unskilled labor he can draw upon.
Another pair of prior inventors are Wachsmann and Gropius, who disclosed a prefabricated building in 1942, in U.S. Pat. No. 2,355,192. Their wall panels have a disadvantage similar to Rappleyea's, for the surfaces of their frameworks intended for the inside surfaces of their buildings are contoured somewhat differently than their outside surfaces. More significantly, the wooden members they employ as studs, for instance, are all specially prepared to form connections of 4 members butting together to form a cross even when only two panels are joined in a flat wall. They also employ a rather complicated metal connector which has many parts fitting into grooves and slots formed in the wooden studs. Each stud must be twice chamfered for such an interfit, and then routed to provide the grooves and slots, requiring some expertise in cabinetry. Such a system is so complex and costly that it is small wonder that it is not seen on the commercial market.
The most relevant art with respect to wedge connectors appears to be disclosed in Australian Pat. No. 117,947, issued in 1944 to L. F. Irwin. Irwin discloses a headed dowel connecting a pair of timbers, the free end of the dowel cooperating with a wedge having a tapered slot which is driven transversely to the dowel axis, the sides of the slot digging into the dowel to put it in tension. Irwin discloses nothing to prevent loosening of the connection by motion of the wedge in the opposite direction, and none has been found.